Tear meniscus height agreement and reproducibility between two corneal topographers and spectral-domain optical coherence tomography.

CLINICAL RELEVANCE: Tear meniscus height (TMH) is an important clinical marker in dry eye diagnosis and management. PURPOSE: To evaluate the reproducibility and agreement of TMH measurements in non-clinical participants using the Oculus Keratograph 5 M, Medmont Meridia, and Spectral-domain optical coherence tomography (Spectralis SD-OCT). METHODS: Fifty-six participants (mean 43.8 ± 22.4 years) were recruited for this cross-sectional study. Image acquisitions were performed on the three devices, sequentially and randomized. The repeatability and reproducibility of inter-observer and inter-device analysis were performed. Repeated measures ANOVA and Bland-Altman Plots were used to evaluate the agreement between devices. RESULTS: The mean TMH with the Oculus Keratograph 5 M, Medmont Meridia and Spectralis SD-OCT were 0.29 ± 0.16 mm, 0.24 ± 0.09 mm and 0.27 ± 0.16 mm, respectively. There were no significant inter-observer differences (paired t-tests, p < 0.001). All the devices exhibited good inter-observer reliability (ICC ≥ 0.877), and good repeatability (CV ≤ 16.53%). Inter-device reliability is moderate (ICC = 0.621, p < 0.001). Repeated measures ANOVA revealed that TMH measurements given by the Spectralis SD-OCT are not significantly different from the Oculus Keratograph 5 M (p = 0.19) and the Medmont Meridia (p = 0.38). TMH measurements from Oculus Keratograph 5 M were significantly higher than those from Medmont Meridia (p = 0.02). Correlations between the mean TMH and the difference in the TMH measurements were positive for Oculus Keratograph 5 M and Medmont Meridia (r2 = 0.62, p < 0.001), negative for Medmont Meridia and Spectralis SD-OCT (r2 = -0.59, p < 0.001), and not significant for Oculus Keratograph 5 M and Spectralis SD-OCT (r2 = 0.05, p = 0.74). A strong correlation was found for TMH measured with all devices (r2 = 0.55 to 0.81, p < 0.001). CONCLUSIONS: The Oculus Keratograph 5 M, Medmont Meridia, and Spectralis SD-OCT provide reliable and reproducible inter-observer TMH measurements. Inter-device reliability is moderate, with a close correlation between Spectralis SD-OCT and the Oculus Keratograph 5 M. Oculus Keratograph 5 M and Medmont Meridia are repeatable devices appropriate for the measurement of TMH, but they are not interchangeable in clinical practice.

Eye discomfort at close work in Portuguese university students: A comparative analysis between the pre-COVID and confinement period.

BACKGROUND: Many individuals experience visual symptoms associated with near work. The level of discomfort appears to increase with the amount of digital screen use. OBJECTIVE: To study the eye discomfort with near tasks in university students in the pre-COVID period and in the period of confinement due to the pandemic. METHODS: Two independent samples of students, aged between 18 and 35 years, were used to assess symptomatic behaviour with the Convergence Insufficiency Symptom Survey (CISS) questionnaire. In the pre-COVID period the sample had 342 participants, 64.6% females and in the COVID period 322 students participated, 71.4% females. The study of differences was carried out by the Mann-Whitney U test. The interpretation of the statistical inference was performed for a significance level≤0.05. RESULTS: There was an increase in the number of symptomatic cases in the COVID period without statistical evidence of differences in the frequency of symptoms reported in the two periods. The dimensions "somatic sensations" and "cognitive performance" were the typology of symptoms that most contributed to visual complaints with near vision. There was a significantly different symptomatic behaviour between genders in the period of confinement (p = 0.001), worsening in females and improving in males. CONCLUSION: These findings suggest that females and males exposed to digital environments, over time, may exhibit different symptomatic behaviour. Our results suggest that boys adapt more quickly than girls. Factors that predispose to these changes, aetiology and potential intervention actions still need further study.

Reduced visual acuity in children from 5 to 6 years old, with LEA chart.

PURPOSE: To assess visual acuity in 5-year-old children with LEA chart and to estimate the frequency of reduced visual acuity in this age. METHOD: Study aimed at children attending the last year of preschool education in Public Kindergartens and Private Social Solidarity Institutions (IPSS) under the influence Regional Health Administration of the Médio Tejo, in Portugal. The 15-line LEA charts at 3 m were used and the presentation visual acuity was measured monocularly starting with the right eye. The ETDRS-fast methodology was used. RESULTS: A total of 3072 children participated, being 51% male and 54% from rural area. A rate of 13.7% children with a reduced level of visual acuity was found, that is, visual acuity worse or equal to 0.2 logMAR in at least one eye, or an interocular difference greater than two lines. CONCLUSION: This research shows that reduced VA frequency rate in children between 5 and 6 years old is high. The literature presents amblyopia (refractive and/or strabismic) and uncorrected refractive errors without amblyopia as the main cause of reduced VA in childhood, and these anomalies negatively affect child development, especially at the educational level. Reduced VA interferes with performance on a number of key tasks in the learning process. Thus, it is important to preserve the running program to identify these deficits and lead to their correction before the beginning of the school stage.

Factor structure of the convergence insufficiency symptom survey questionnaire.

The purpose of this study is to analyze the factorial structure of the Convergence Insufficiency Symptom Survey questionnaire with 15 items, in order to identify latent dimensions that can contribute to a more focused implementation. The questionnaire was self-administered in paper by 183 university students, in the age span of 18 to 30. Both Kaiser-Meyer-Olkin measure and Bartlett's sphericity test were performed to ensure the validity of the factorization. In order to analyze the principal components, factors which obtained eigenvalues greater than 1 were chosen. The extraction of factors was performed after computing a Promax rotation and a Kaiser criterion. In each extracted factor, the internal consistency was used to prove its reliability. Bartlett's sphericity test was statistically significant (p <0.001), and the Both Kaiser-Meyer-Olkin test was 0.89, confirming the factorization of this instrument. Exploratory factor analysis followed by a Promax rotation and scree plots graphic, extracted three factors that explained 62.1% of the total variance. The composition of each factor suggests the following meanings: Factor 1 (somatic sensation) includes 8 of 15 items; Factor 2 (impaired vision) includes 3 of 15 items; Factor 3 (cognitive performance) includes 4 of 15 items. Cronbach's alpha coefficient demonstrated good internal consistency (α> 0.75) in three dimensions. The multivariate statistical analysis of the Convergence Insufficiency Symptom Survey revealed a three-factor structure, so new forms of questionnaire analysis can be designed in order to obtain gains in the management of a symptomatic patient, using 3 subscores, one for each factor, instead of a total score. The factorial structure of the questionnaire can be used with a high level of confidence in future investigations, which aim to assess which dimensions are most affected in each type of visual changes and develop more targeted therapeutic performances.

Transcranial Magnetic Stimulation in Adults With Amblyopia.

BACKGROUND: Through transcranial magnetic stimulation (TMS) it is possible to change cortical excitability of the visual cortex, and to influence binocular balance. The main goal of our study is to assess the effect of transcranial magnetic stimulation, specifically theta burst stimulation (TBS), in a group of amblyopic volunteers measuring several visual parameters: visual acuity, suppressive imbalance, and stereoacuity. METHODS: Thirteen volunteers aged 19 to 24 years, randomly split in 2 groups, underwent 1 session of continuous TBS, stimulating the right occipital lobe. The first group with 8 volunteers was exposed to active stimulation with cTBS, and the other group with 5 volunteers was exposed to placebo stimulation. RESULTS: Significant improvements in visual acuity, suppressive imbalance, and stereoacuity were found in the amblyopic eye after cTBS. The average value of amblyopia in visual acuity before stimulation was 0.32 ± 0.20 logMar and after cTBS was 0.19 ± 0.17 logMar. The mean value for the control group before placebo stimulation was 0.28 ± 0.17 and after placebo stimulation was 0.28 ± 0.16. The suppressive imbalance in the group of amblyope subjects stimulated before cTBS was 0.26 ± 0.18 and after was 0.12 ± 0.12; the suppressive imbalance of the control group before the placebo stimulation was 0.34 ± 0.37 and after was 0.32 ± 0.40. CONCLUSIONS: Visual acuity, suppressive imbalance, and stereoacuity had significant enhancements compared with baseline after cTBS over the right occipital lobe in an ambliopic population.

Visual performance: validation of the inventory of visual efficiency in students / Desempenho visual: validação do inventário de eficiência visual em estudantes

Purpose: Translate and adapt the COVD-QoL questionnaire to Portuguese language and culture and assess the psychometric properties of the translated questionnaire. Methods: The questionnaire was adapted according to the methodology recommended by the literature. The final version of visual symptoms and quality of life questionnaire adapted to Portuguese (QSL-QOL) was applied in 130 volunteers, aged 18 to 30 years and 36 subjects completed the questionnaire at two different times. Results: The results showed good internal consistency for the full version with 30 items (α = 0.894) and for the short version with 19 items (0.858). The test re-test revealed an average of differences between the first and second evaluation of 0,917 points (SD = ± 4.813) which indicates a minimum bias between the two applications. Conclusions: The Portuguese version of COVD-QoL showed good psychometric properties and has been shown to be applicable to the Portuguese population, to evaluate visual discomfort associated with near vision in higher education students.

Objetivo:Traduzir e adaptar transculturalmente o questionário COVD-QoL para a língua portuguesa e avaliar as propriedades psicométricas do questionário traduzido.Métodos:O questionário foi adaptado segundo a metodologia recomendada pela literatura. A versão final do questionário de sintomas e eficiência visual adaptado à língua portuguesa (IEV – Inventário de eficiência visual) foi aplicada em 130 indivíduos, com idades compreendidas entre os 18 e os 30 anos e 36 sujeitos responderam ao questionário em dois momentos distintos.Resultados:Os resultados evidenciam uma boa consistência interna tanto para a versão completa, com 30 itens (α = 0,894) como para a versão curta, com 19 itens (0,858). O teste reteste revelou uma média de diferenças entre a primeira e a segunda avaliação de 0,917 pontos (SD=±4,813) o que indica um viés mínimo entre as duas administrações.Conclusão:O questionário traduzido, apresentou boas propriedades psicométricas e demonstrou ser aplicável à população portuguesa, para se avaliar a eficiência visual associada à visão de perto, em estudantes do ensino superior.